So I need to prompt the user for 4-6 numbers and display them in reverse order:

here's what I have
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<script type="text/javascript">
function ultraprompter(){

numberofwords=prompt("Enter a number 4-6 in the text field", "Enter number here");
if (numberofwords=="4"){
word1=prompt("Enter a word");
word2=prompt("Enter a word");
word3=prompt("Enter a word");
word4=prompt("Enter a word");
if (word4!=""){
document.writeln("<p align=\"center\">"+word4);
}
else{
document.writeln("<p align=\"center\">Blank word, try again");
}
if (word3!=""){
document.writeln("<p align=\"center\">"+word3);
}
else{
document.writeln("<p align=\"center\">Blank word, try again");
}
if (word2!=""){
document.writeln("<p align=\"center\">"+word2);
}
else{
document.writeln("<p align=\"center\">Blank word, try again");
}
if (word1!=""){
document.writeln("<p align=\"center\">"+word1);
}
else{

document.writeln("<p align=\"center\">Blank word, try again");
}
}
if (numberofwords=="5"){
word1=prompt("Enter a word");
word2=prompt("Enter a word");
word3=prompt("Enter a word");
word4=prompt("Enter a word");
word5=prompt("Enter a word");
if (word5!=""){
document.writeln("<p align=\"center\">"+word5);
}
else{
document.writeln("<p align=\"center\">Blank word, try again");
}
if (word4!=""){
document.writeln("<p align=\"center\">"+word4);
}
else{
document.writeln("<p align=\"center\">Blank word, try again");
}
if (word3!=""){
document.writeln("<p align=\"center\">"+word3);
}
else{
document.writeln("<p align=\"center\">Blank word, try again");
}
if (word2!=""){
document.writeln("<p align=\"center\">"+word2);
}
else{
document.writeln("<p align=\"center\">Blank word, try again");
}
if (word1!=""){
document.writeln("<p align=\"center\">"+word1);
}
else{

document.writeln("<p align=\"center\">Blank word, try again");
}
}

if (numberofwords=="6"){
word1=prompt("Enter a word");
word2=prompt("Enter a word");
word3=prompt("Enter a word");
word4=prompt("Enter a word");
word5=prompt("Enter a word");
word6=prompt("Enter a word");
if (word6!=""){
document.writeln("<p align=\"center\">"+word6);
}
else{
document.writeln("<p align=\"center\">Blank word, try again");
}
if (word5!=""){
document.writeln("<p align=\"center\">"+word5);
}
else{
document.writeln("<p align=\"center\">Blank word, try again");
}
if (word4!=""){
document.writeln("<p align=\"center\">"+word4);
}
else{
document.writeln("<p align=\"center\">Blank word, try again");
}
if (word3!=""){
document.writeln("<p align=\"center\">"+word3);
}
else{
document.writeln("<p align=\"center\">Blank word, try again");
}
if (word2!=""){
document.writeln("<p align=\"center\">"+word2);
}
else{
document.writeln("<p align=\"center\">Blank word, try again");
}
if (word1!=""){
document.writeln("<p align=\"center\">"+word1);
}
else{

document.writeln("<p align=\"center\">Blank word, try again");
}
}


else{
document.write("<p align=\"center\">stop it");
}

}


</script>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
</head>

<body onload="ultraprompter()">
</body>
</html>


The only things that don't work are this:
1. It doesn't display t
(continued)
the first number entered if the user chose to enter 6 numbers

2. It doesn't display anything when something other than a number 4-6 is entered, it is supposed to say "stop it"